diff --git a/awx/main/dispatch/worker/callback.py b/awx/main/dispatch/worker/callback.py
index b47b648086..5673bbb9b9 100644
--- a/awx/main/dispatch/worker/callback.py
+++ b/awx/main/dispatch/worker/callback.py
@@ -77,13 +77,13 @@ class CallbackBrokerWorker:
 
     MAX_RETRIES = 2
     INDIVIDUAL_EVENT_RETRIES = 3
-    last_stats = time.time()
-    last_flush = time.time()
     total = 0
     last_event = ''
     prof = None
 
     def __init__(self):
+        self.last_stats = time.time()
+        self.last_flush = time.time()
         self.buff = {}
         self.redis = get_redis_client()
         self.subsystem_metrics = s_metrics.CallbackReceiverMetrics(auto_pipe_execute=False)
diff --git a/awx/main/tests/functional/commands/test_callback_receiver.py b/awx/main/tests/functional/commands/test_callback_receiver.py
index 145c48d605..f585864cb2 100644
--- a/awx/main/tests/functional/commands/test_callback_receiver.py
+++ b/awx/main/tests/functional/commands/test_callback_receiver.py
@@ -48,7 +48,7 @@ class TestCallbackBrokerWorker(TransactionTestCase):
         worker = CallbackBrokerWorker()
         events = [InventoryUpdateEvent(uuid=str(uuid4()), **self.event_create_kwargs())]
         worker.buff = {InventoryUpdateEvent: events}
-        worker.flush()
+        worker.flush(force=True)
         assert worker.buff.get(InventoryUpdateEvent, []) == []
         assert InventoryUpdateEvent.objects.filter(uuid=events[0].uuid).count() == 1
 
@@ -61,7 +61,7 @@ class TestCallbackBrokerWorker(TransactionTestCase):
             InventoryUpdateEvent(uuid=str(uuid4()), stdout='good2', **kwargs),
         ]
         worker.buff = {InventoryUpdateEvent: events.copy()}
-        worker.flush()
+        worker.flush(force=True)
         assert InventoryUpdateEvent.objects.filter(uuid=events[0].uuid).count() == 1
         assert InventoryUpdateEvent.objects.filter(uuid=events[1].uuid).count() == 0
         assert InventoryUpdateEvent.objects.filter(uuid=events[2].uuid).count() == 1
@@ -71,7 +71,7 @@ class TestCallbackBrokerWorker(TransactionTestCase):
         worker = CallbackBrokerWorker()
         events = [InventoryUpdateEvent(uuid=str(uuid4()), **self.event_create_kwargs())]
         worker.buff = {InventoryUpdateEvent: events.copy()}
-        worker.flush()
+        worker.flush(force=True)
 
         # put current saved event in buffer (error case)
         worker.buff = {InventoryUpdateEvent: [InventoryUpdateEvent.objects.get(uuid=events[0].uuid)]}
@@ -113,7 +113,7 @@ class TestCallbackBrokerWorker(TransactionTestCase):
 
         with mock.patch.object(InventoryUpdateEvent.objects, 'bulk_create', side_effect=ValueError):
             with mock.patch.object(events[0], 'save', side_effect=ValueError):
-                worker.flush()
+                worker.flush(force=True)
 
             assert "\x00" not in events[0].stdout
 
diff --git a/awxkit/awxkit/api/mixins/has_create.py b/awxkit/awxkit/api/mixins/has_create.py
index 21f37fe7a2..909a36b50e 100644
--- a/awxkit/awxkit/api/mixins/has_create.py
+++ b/awxkit/awxkit/api/mixins/has_create.py
@@ -61,7 +61,7 @@ def separate_async_optionals(creation_order):
             continue
         by_count = defaultdict(set)
         has_creates = [cand for cand in group if hasattr(cand, 'dependencies')]
-        counts = {has_create: 0 for has_create in has_creates}
+        counts = dict.fromkeys(has_creates, 0)
         for has_create in has_creates:
             for dependency in has_create.dependencies:
                 for compared in [cand for cand in has_creates if cand != has_create]:
@@ -212,7 +212,7 @@ class HasCreate(object):
         dependency_store = kw.get('ds')
         if dependency_store is None:
             deps = self.dependencies + self.optional_dependencies
-            self._dependency_store = {base_subclass: None for base_subclass in deps}
+            self._dependency_store = dict.fromkeys(deps)
             self.ds = DSAdapter(self.__class__.__name__, self._dependency_store)
         else:
             self._dependency_store = dependency_store.dependency_store